Induction-motor winding.



J. E, WEBSTER.

INDUCTION MOTOR WINDING.

APPLICATION FILED JULY s, 1908.

Patented June 30, 1914.

% INVENTOR ATTO-RNEY UNITED STATES PATENT OFFIGE.

JOH E. WEBSTER, or PITTSBUBGH,-PENNSYLVANIA, ASSIGNOR, BY MnsNE Ass'rsn MENTS, mo WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, or nesr PITTSBURGH, PENNSYLVANIA, A CORPORATION or rENNsYLvANIA.

/ INDUCTION-MOTOR WINDING.

, Specification critters Patent. ,I'ate t d J 39 lgi Application filed July 6, .1908. Serial 110. 442,208.

,windings'forthe secondary members 'of induction motors;

The object of' my invention is to prov de improved short-circuiting 'end rings for mduction motor windings of the cage type that shall be relatively inexpensive to construct and that shall maintain an excellent electrical connection with the bar conductors upon the ends of which they are mounted.

In 'order to accomplish the aforesaid objective results I combine a plurality of ring segment laminae having dovetail-shaped openings, with bar conductors of dove-tail form in cross section, by seating the ends of the conductors in said openings.

Figure 1 of the accompanying drawings is a sectional elevation of a portion of a rotor of an induction motor having a cage winding constructed in accordance with my invention. Fig. 2 is an end elevation of the motor portion shown in Fig. 1, and Fig. 3

is a view similar to Fig. 1 which illustrates a slightly modified end ring construction.

Referring to Figs. 1 and 2 of the drawings, a magnetizable core structure jl, having the usual slots 2 near its periphery, is mounted on a spider 3 and is held in posi: tion by clamping'rings 4. Rods or bars 5 of conducting material. are partially located in the slots 2 and project outwardly therefrom to form portions of an induction motor winding of the squirrel-cage type. The ends of the bars or rods 5 are short-circuited by rings "6' composed of segments 7 each of which is a punched or stamped plate of conducting material having a plurality of openings 8 which are adapted to fit closely over the ends of the bars 5. The ends of each segment 7 are notched to engage the sides of twobars that are connected together by another segment, the complete ring comprising a plurality of segments so disposed that the spaces be tween them are staggered. By this means, adjacent segments in the same plane are materially separated from each other so that the radiating surface of the assembled ring is increased. The shape of the openings in the end ringsand the corresponding shape of the bars is susceptible of modification but I prefer the dove-tail form'illustrated in the drawings for the following reasons: The wedging action between the bars and the ring segments produces an excellent electrical connection between. the inner and side surfaces of the bars and the corresponding walls of the ring openings and serves to effectively withstand the action of centrifugal force to which the bars are subjected inv operation, and also insures a maximum amount of surface contact between the bars and the ring segments. The large side-sur-v face contact is important because the portions of the rings whichare outside the bars are necessarily thin and, in fact, may be omitted entirely in some cases.

It may be found desirable to divide the complete ring into parts, as shown in Fig. 3.; in order to still further improve the venjtilation of the winding. The electrical conpressed close together, may be improved by a well known soldering process, if desired. I claim as my invention: 1. In a cage winding for dynamo-electric machines, the combination with a plurality of bars having dove-tail form in cross section, of short circuiting end rings therefor. comprising laminated segmental rings having dove-tail openings to receive the ends of the bars, the ring segments in each plane being spaced apart and those in ad-' jacent planes being in staggered relation to each other.

2. A cage Winding comprising bars of wedge shape and relatively large radial depth 111 cross section and having their narrow edges disposed outwardly, and laminated end rings having holes of the same form as the ends of the bars and fitted thcreon, whereby a Wedgmg action takes place nection between the ring segments which are mama}; Contact surfae-es of the bars and In testimon' whereof I have hereunto rings. subscrlbed my name tins 2nd day of July, 10

:3. Wnmmg cemprlsmg bars 0t 1908.

".O'YJ iflfi form in crass seciien and lahli- H EB TER. natad e116; rings hzzvmg ho es 111 Winch the I J0 N W ends of the bars are seated, the 12111111152 1n Nltnessesr @611 plane bang corngmsed 01 spac ad seg- VEEYL BRQUGHTON,

mania BIRNEY HD1235. 

